Chalk line marker



FIG. 1 is a front elevational view of a chalk line marker showing our new design;

FIG. 2 is a left side elevational view thereof, the right side elevational view being a mirror image;

FIG. 3 is a top plan view thereof;

FIG. 4 is a bottom plan view thereof; and,

FIG. 5 is a rear elevational view thereof. 

The ornamental design for a chalk line marker, as shown and described. 